Pre-set torque measuring device of the beam type

ABSTRACT

This disclosure embodies the concept of utilizing mechanical expedients comprising torque turning load resisting flexure instrumentalities, other than conventional springs, between the work engaging member and the handle member constituting a preset torque measuring wrench. The work engaging and handle members are operatively connected by combined roller and flex beam components which are calibrated to offer a predetermined turning load resistance to roller slip lever engagement measured by the flex beam roller carrier in confronting relation to a work engaging fluted revoluble member and the turning handle member. The beam flex may be constant or adjustable by means of a calibrated and adjustable fulcrum disposed in relation to the flex beam.

United States Patent [72] Inventor Talmage 0. Green Schaumburg, Ill. [21 Appl. No. 855,819 [22] Filed Sept. 8, 1969 [45] Patented Aug. 3, I971 [73] Assignee Snnp-on Tools Corporation Kenosha, Wis.

[54] PRE-SET TORQUE MEASURING DEVICE OF THE BEAM TYPE 10 Claims, 4 Drawing Figs.

[52} 0.8. CI til/52.4 [5 1] Int. Cl B25b [50] Field of Search 81/524 [56] References Cited UNITED STATES PATENTS 2,556,587 6/1951 Keen 81/524 3,236,127 2/1966 Knudsen et al. 81/524 3,279,286 l0/l966 Larson 8 l/52.4

2,852,972 9/1958 Larson 81/524 FOREIGN PATENTS 820,275 ll/l951 Germany 81/524 Primary Examiner-James L. Jones, Jr. Attorney- Harry C. Alberts ABSTRACT: This disclosure embodies the concept of utilizing mechanical expedients comprising torque turning load resisting flexure instrumentalities, other than conventional springs, between the work engaging member and the handle member constituting a preset torque measuring wrench. The work engaging and handle members are operatively connected by combined roller and flex beam components which are calibrated to offer a predeten-nined turning load resistance to roller slip lever engagement measured by the flex beam roller carrier in confronting relation to a work engaging fluted revoluble member and the turning handle member. The beam flex may be constant or adjustable by means of a calibrated and adjustable fulcrum disposed in relation to the flex beam.

PklE-SIET TUlltQlUlE MEASllJlltllNG DIET/fill; T TTilE BEAM Tit'lilli This invention relates to torque wrenches and more particularly to preset torque wrenches having special application to industrial uses on production line operations, although it may be employed with equal advantage by mechanics and others servicing individual devices such as but not limited to automobiles and the like.

It contemplates more especially the simplification of preset torque wrenches of the type described and claimed in Letters Pat. No. 2,852,972, dated Slept. 23, 1958 and No. 3,279,286, dated Oct. id, 1966 providing a wide range for prescribed loads which may be applied for fastener tightening and loosening so that any excess turning force applied will mechanically release the turning connection between the handle and work engaging member to preclude load turning beyond the preset amount.

With the teachings of the present invention, the torque resisting flexure is measured between a work engaging member and a handle member that are operatively connected together by beam-roller type of carrier elements which is an exceedingly simple and composite measuring element having a minimum friction or substantially frictionless component to effectuate a release therebetween when the applied turning load exceeds the preset resisting flexure forces. This is accomplished in the preferred embodiment for illustrative purposes by utilizing a ratchet-type revoluble member cooperating with roller beam resisting elements which retain the engagement between the work engaging member and the handle member until the preset turning load permits the roller detents to ride over the ratchet-type circumferential member responsive to applying a load in excess of the resistance ofiered by the flexible beam serving as a roller carrier. This eliminates the inaccuracy of friction reacting elements and conventional springs as well as introducing human errors in reading meters or visual indicators to insure fastener tightness by the uniform application of torque loads in repeated tightening operations on a production line or in other applications.

One object of the present invention is to simplify the construction and operation of devices of the character mentioned.

Another object is to provide a simplified and more accurate mechanical release for torque wrenches and the like when the turning load exceeds the preset limit.

Still another object is to provide a simple and inexpensive torque turning mechanism which will release the turning connection when the applied turning load imparts a flex to a beam that exceeds the preset calibrated amount.

A further object is to provide a torque wrench which will release the mechanical connection between the work engaging and handle members responsive to attaining a preset load turning applied force between a roller slip connection and a flex beam serving as a carrier therefor.

A still further object is to provide improved and less expensive adjustable flexure presetting and release means to preclude any applied force in excess of the predetermined setting thereof.

Still a further object is to provide a work engaging and handle member with simple and inexpensive releasable connectors of the roller clutching and declutching type utilizing a flex beam roller carrier which provides a torque resisting flexure cooperating with the revoluble serrated or fluted work engaging member element.

Other objects and advantages will appear from the following description of an illustrated embodiment of the present invention.

FIG. l is a front view in full section of a device taken substantially along line l-I of H6. 2 and embodying features of the present invention.

lFlG. 2 is a fragmentary sectional view in elevation taken substantially along line lI-Il of FIG. ll.

FIG. 3 is an enlarged fragmentary sectional view in elevation of the work engaging head portion of the torque wrench taken substantially along line Ill-ill of F l6. 1.

FIG. il is a composite perspective view of the individual parts comprising the assembled head portion of the device illustrated in H6. 3.

The structure selected for illustration is not intended to serve as a limitation upon the scope or teachings of the invention, but is merely illustrative thereof. There may be considerable variations and adaptations of all or part of the teachings depending upon the dictates of commercial practice. The present invention comprises an elongated tubular handle member it) which may take a variety of shapes but, in this instance, is oblong and somewhat tapered to present an enlarged rounded head portion Ill and a substantially rectangular handle end portion 112 to serve overall as a combined casing and handle member ill).

The casing in this instance, comprises complements] chambered half-sections lit-id assembled with the interiorly confined operating instrumentalities to be hereinafter described by resort to suitable studs or rivets extending through apertures -1b, although other retainers such as a screw fasteners may be resorted to for that purpose of assembled connection therebetween. A revoluble work engaging revoluble member 17 is provided with a peripherally cross-fluted cylindrical surface developed by rounded node and valley contours llh-llf respectively. The contoured flutes lid-119 confront a beam reacting instrumentality as will appear more fully hereinafter. The fluted work engaging member ll'l' terminates in a square axial shank 20 to detachable engage conventional wrench sockets of various sizes for turning threaded nuts and other fasteners in the usual and well-known manner. A spring impelled ball detent 21 is fitted to the axial shank 20 to retain the wrench sockets thereon and afford easy replacement with different socket sizes.

The revoluble working engaging member 17 is journaled in confronting plates 22-23 detachable held by screw fasteners, rivets or otherwise in interior contact with the complementally shaped head portions of the casing sections iii-1d. The work engaging member 17 is axially recessed as at 24 and 2d to receive roller bearing raceways 2b and. 2.7 that are confined by appropriate bearing cap and bushing 2b29, respectively, fitted into complemental and aligned openings 30-31 and 32-33 in the confronting casing sections 113-14 and the plates M-JZ, respectively. This provides a rotary work engaging member 17 that operates with minimum friction and presents the fluted periphery lid-l9 thereof for cooperation with a small diameter cylindrical roller pin M which is complemental to and freely rolls in the valleys 19 between the nodes lift of the fluted peripheral surface of the work engaging member 17.

it has been found that the use of friction and conventional springs to determine the release of a preset load in torque measuring devices, is not sufficiently accurate, uniform and dependable for determining the measured load release in precision torque measuring devices and to avoid these deficiencies, a comparatively frictionless roller beam reactor element is provided between the revoluble work engaging member 117 and the interior of the handle member 10. To this end, an elongated roller pin 34 is in surface contact with a comparatively larger diameter roller 35 having axial mounting trunnions 36-37 journaled in spaced confronting carrier plates 38-39 substantially triangular in overall shape. The carrier plates Lid-39 have openings illi-41 provided in the forward upper edge thereof to freely accommodate the roller pin 3d, and apertures sz-ss proximate thereto to receive the roller trunnions 36-37 for free rotary mounting of the roller 35 which is in surface contact with the roller pin 34.

The carrier plates Iih-M have two other apertures i i-45 and ss-sv in the remaining corners thereof to provide a pivotal mount for a pin 48 that extends therebetween and into correspondingly positioned apertures 115-416 and l'l6 provided in the casing and interior mounting plates 13-l4 and 3h-39, respectively. The rivet or stud pin 43 pivotally mounts the carrier plates 38-39 to the casing sections 13- id to serve the dual purpose of retaining the latter assembled. The apertures dh-di' in the carrier plates Sid-39 in turn carry a rivet pin 49 that extends through an aperture 50 in one end of an elongated flex beam 51. The beam 51 extends into the hand applying end of the handle member sections 13-14 so that its free end 52 will be in the path of a fulcrum protruberance 53 provided on the interior edges of the casing sections 13-14. This provides two spaced fulcrums 49-53 between which the beam 51 will flex as the turning load is applied to the handle member 10. This movement roller rotation continues until the beam flex is sufficient to turn the carrier plates 38-39 with its roller 35 rotating oppositely to the flute roller pin 34 to allow frictional separation therebetween.

This minute separation of the roller 35 and roller pin 34 measured by the flex in the calibrated beam 51 pursuant to applying a preset turning load on a'screw fastener, allows the roller pin 34 to ride over the adjacent node 18 in the fluted work engaging member 17, and the consequent slip precludes further application of any turning load at a preset value. The work engaging member 17 through its fastener engaging socket in the shank 20, is then disengaged from the screw fastener and the beam 51 returns to its initial straight or unflexed condition and position. Thereupon, the roller pin 34 i and roller 35 return to their contacting relative positions to enable repeated applications of turning and tightening loads to other similar screw fasteners.

The preset load may be varied on any given torque wrench to adjust the accuracy thereof after extended use or to change the value of the load at which disengagement and release takes place, by providing an adjustable intermediate fulcrum support screw stud 54 that extends through an interior screw body mount 55 attached to the edge of the casing sections 13-14 opposite to the fulcrum 53. A turn knob 56 is attached to the fulcrum screwstud 54 (FIG. 1) to enable the turning thereof for changing the flex of the beam 51 to require increased or lesser loads at which the preset release is effected. The knob 56 may be calibrated on its flat surface in relation to a mark on the casing exterior to afl'ord ready and precise adjustment.

It will be apparent from the foregoing description of the structure that engagement and disengagement between the fluted work engaging member and the roller-beam carrier is accomplished without direct friction and with minimum indirect rolling friction that is inconsequential and rather uniform as contrasted with direct friction which varies depending upon wear, lubrication, and the presence of foreign substances. It should be noted that the roller 35 rides on the internal surface I 1 of the casing (FIG. 1) during the pivotal movement of the carrier plates 38-39 to afford compactness of design, guided support movement therefor, and uniformity of reaction attendant with minimum friction for insuring measurement accuracy in releasing the applied turning load at any preset value with the capacity of the wrenching instrumentalities described herein. Roller reaction as against direct sliding friction, results in minimal wear, friction, and uniformity in the release coefficient without any requisite lubrication which is detrimental to uniformly accurate functioning results in structures of this type.

While I have illustrated and described a preferred embodiment of this invention, it must be understood that the invention is capable of considerable variation and modification without departing from the spirit of the invention and its concepts. I, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

lclaim:

1. In a torque measuring wrench, the combination with a rigid handle member, of a work engaging revoluble member in said handle member, of a turning load torque responsive member serving as a bending beam in said handle member adapted to yield independently of the latter and commensurately with torque loads transmitted thereto in conjunction with the turning of said handle member and said working engaging member, a reactor carrier interposed between said work en aging member and said turning load torque responsive ben ing beam member are m clutching operative engagement through said reactor carrier to transmit the applied load to the latter when the turning load is below a preset value and for declutching said torque responsive member when the applied load is beyond the preset value of said carrier and torque responsive member.

2. In a torque wrench of the type defined in claim 1 wherein the work engaging member has a fluted peripheral surface and a complemental roller is journaled in said reactor carrier to engage or ride over said fluted peripheral surface depending upon the flex in said bending beam.

3. In a torque wrench of the type defined in claim 2 wherein the torque responsive member is fulcrummed between said reactor carrier and said handle member to bend responsive to the applied load.

4. In a torque wrench of the type defined in claim 2 wherein plural rollers contact each other during the clutching operative engagement between said work engaging member and said carrier, and separate when said torque responsive member flexes beyond a predetermined preset value.

5. In a torque wrench defined in claim 4 the reactor carrier is pivoted to said handle member and serves as an end fulcrum for said torque responsive bending member.

6. in a torque wrench of the type defined in claim 2 wherein said fluted work engaging member and said reactor carrier each have rollers rotatively mounted therein for frictional contact and separation depending upon the position of the torque responsive member.

7. In a torque wrench of the type defined in claim 6 wherein said reactor carrier is pivoted and said torque responsive member is connected therewith.

8. In a torque wrench defined in claim 7 wherein said torque responsive member comprises a flexible beam having spaced fulcrums for support to bend commensurate with the applied torque turning load and varies the position of said reactor carner.

9. In a torque wrench defined in claim 3 wherein one of said fulcrums is adjustable to vary the preset load for release of said work engaging member.

10. In a torque wrench defined in claim 8 wherein the bending beam is fulcrummed between said reactor carrier and said handle member, and an adjustable fulcrum is interposed between said handle member and said bending beam to vary the preset load for release of said work engaging member. 

1. In a torque measuring wrench, the combination with a rigid handle member, of a work engaging revoluble member in said handle member, of a turning load torque responsive member serving as a bending beam in said handle member adapted to yield independently of the latter and commensurately with torque loads transmitted thereto in conjunction with the turning of said handle member and said working engaging member, a reactor carrier interposed between said work engaging member and said turning load torque responsive bending beam member are in clutching operative engagement through said reactor carrier to transmit the applied load to the latter when the turning load is below a preset value and for declutching said torque responsive member when the applied load is beyond the preset value of said carrier and torque responsive member.
 2. In a torque wrench of the type defined in claim 1 wherein the work engaging member has a fluted peripheral surface and a complemental roller is journaled in said reactor carrier to engage or ride over said fluted peripheral surface depending upon the flex in said bending beam.
 3. In a torque wrench of the type defined in claim 2 wherein the torque responsive member is fulcrummed between said reactor carrier and said handle member to bend responsive to the applied load.
 4. In a torque wrench of the type defined in claim 2 wherein plural rollers contact each other during the clutching operative engagement between said work engaging member and said carrier, and separate when said torque responsive member flexes beyond a predetermined preset value.
 5. In a torque wrench defined in claim 4 the reactor carrier is pivoted to said handle member and serves as an end fulcrum for said torque responsive bending member.
 6. In a torque wrench of the type defined in claim 2 wherein said fluted work engaging member and said reactor carrier each have rollers rotatively mounted therein for frictional contact and separation depending upon the position of the torque responsive member.
 7. In a torque wrench of the type defined in claim 6 wherein said reactor carrier is pivoted and said torque responsive member is connected therewith.
 8. In a torque wrench defined in claim 7 wherein said torque responsive member comprises a flexible beam having spaced fulcrums for support to bend commensurate with the applied torque turning load and varies the position of said reactor carrier.
 9. In a torque wrench defined in claim 3 wherein one of said fulcrums is adjustable to vary the preset load for release of said work engaging member.
 10. In a torque wrench defined in claim 8 wherein the bending beam is fulcrummed between said reactor cArrier and said handle member, and an adjustable fulcrum is interposed between said handle member and said bending beam to vary the preset load for release of said work engaging member. 